A temperature sensor, which is conventionally used for detecting an engine coolant temperature, is shown in FIG. 7A. The temperature sensor has a housing 120, as shown in FIG. 7C, made of brass being engaged to an element support part 140 made of resin. The housing 120 comprises a cylindrical pointed end 122 that accommodates a temperature sensing element 62, a crimping rear end 128, and a hollow space 130 that is perforated axially aligning with an axis CC of the temperature sensor. The element support part 140 includes a support portion that supports the temperature sensing element 62 in the hollow space 130, a flange portion 146 that is sealed by the crimping rear end 128, and a connector portion 142 for electrical connection with an external controller, etc.
A circled portion VIIB in FIG. 7A is expansively shown in FIG. 7B. A gap between the housing 120 and the element support part 140 is sealed by a sealing ring 82 that interposes between an abutment surface 132 of the housing 120 and a recess portion 149 recessing from an abutting front surface 148 of the flange portion 146.
Sealing structures of a temperature sensor is disclosed in Japanese patent documents such as JP-A-2003-139622, JP-A-10-213491, and JP-A-2002-243557.
When the housing 120 has a dent or a scratch on the abutment surface 132 in contact with the sealing ring 82, as shown in FIG. 7B, it cannot protect the temperature sensing element 62 from an outside water. As a result, the element 62 will be corroded by the water permeating from the crimping portion 128. The housing 120, being made of brass for the ease of processing, is prone to a scratch. Further, the housing 120 is easily scratched on the abutment surface 132 by the cylindrical pointed end 122 of other housings 120 when being handled untidily during conveyance. This leads to the loss of hermetic contact described above. Each housing 120 is thus being conveyed in a case with the pointed end 122 inserted in a separate hole in the case. Inserting each housing 120 in a hole is a troublesome task.